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simplify call frame instruction parser

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This commit is contained in:
kcbanner
2023-07-24 10:43:14 -04:00
parent 20ce7455b9
commit d1ed1c167b
1 changed files with 244 additions and 187 deletions
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431
lib/std/dwarf/call_frame.zig
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@@ -50,189 +50,246 @@ const Opcode = enum(u8) {
pub const hi_user = 0x3f;
};
const Operand = enum {
opcode_delta,
opcode_register,
uleb128_register,
uleb128_offset,
sleb128_offset,
address,
u8_delta,
u16_delta,
u32_delta,
block,
fn readBlock(stream: *std.io.FixedBufferStream([]const u8)) ![]const u8 {
const reader = stream.reader();
const block_len = try leb.readULEB128(usize, reader);
if (stream.pos + block_len > stream.buffer.len) return error.InvalidOperand;
fn Storage(comptime self: Operand) type {
return switch (self) {
.opcode_delta, .opcode_register => u8,
.uleb128_register => u8,
.uleb128_offset => u64,
.sleb128_offset => i64,
.address => u64,
.u8_delta => u8,
.u16_delta => u16,
.u32_delta => u32,
.block => []const u8,
};
}
const block = stream.buffer[stream.pos..][0..block_len];
reader.context.pos += block_len;
fn read(
comptime self: Operand,
stream: *std.io.FixedBufferStream([]const u8),
opcode_value: ?u6,
addr_size_bytes: u8,
endian: std.builtin.Endian,
) !Storage(self) {
const reader = stream.reader();
return switch (self) {
.opcode_delta, .opcode_register => opcode_value orelse return error.InvalidOperand,
.uleb128_register => try leb.readULEB128(u8, reader),
.uleb128_offset => try leb.readULEB128(u64, reader),
.sleb128_offset => try leb.readILEB128(i64, reader),
.address => switch (addr_size_bytes) {
2 => try reader.readInt(u16, endian),
4 => try reader.readInt(u32, endian),
8 => try reader.readInt(u64, endian),
else => return error.InvalidAddrSize,
},
.u8_delta => try reader.readByte(),
.u16_delta => try reader.readInt(u16, endian),
.u32_delta => try reader.readInt(u32, endian),
.block => {
const block_len = try leb.readULEB128(usize, reader);
if (stream.pos + block_len > stream.buffer.len) return error.InvalidOperand;
const block = stream.buffer[stream.pos..][0..block_len];
reader.context.pos += block_len;
return block;
},
};
}
};
fn InstructionType(comptime definition: anytype) type {
const definition_type = @typeInfo(@TypeOf(definition));
assert(definition_type == .Struct);
const definition_len = definition_type.Struct.fields.len;
comptime var fields: [definition_len]std.builtin.Type.StructField = undefined;
inline for (definition_type.Struct.fields, &fields) |definition_field, *operands_field| {
const opcode = std.enums.nameCast(Operand, @field(definition, definition_field.name));
const storage_type = opcode.Storage();
operands_field.* = .{
.name = definition_field.name,
.type = storage_type,
.default_value = null,
.is_comptime = false,
.alignment = @alignOf(storage_type),
};
}
const InstructionOperands = @Type(.{
.Struct = .{
.layout = .Auto,
.fields = &fields,
.decls = &.{},
.is_tuple = false,
},
});
return struct {
const Self = @This();
operands: InstructionOperands,
pub fn read(
stream: *std.io.FixedBufferStream([]const u8),
opcode_value: ?u6,
addr_size_bytes: u8,
endian: std.builtin.Endian,
) !Self {
var operands: InstructionOperands = undefined;
inline for (definition_type.Struct.fields) |definition_field| {
const operand = comptime std.enums.nameCast(Operand, @field(definition, definition_field.name));
@field(operands, definition_field.name) = try operand.read(stream, opcode_value, addr_size_bytes, endian);
}
return .{ .operands = operands };
}
};
return block;
}
pub const Instruction = union(Opcode) {
advance_loc: InstructionType(.{ .delta = .opcode_delta }),
offset: InstructionType(.{ .register = .opcode_register, .offset = .uleb128_offset }),
offset_extended: InstructionType(.{ .register = .uleb128_register, .offset = .uleb128_offset }),
restore: InstructionType(.{ .register = .opcode_register }),
restore_extended: InstructionType(.{ .register = .uleb128_register }),
nop: InstructionType(.{}),
set_loc: InstructionType(.{ .address = .address }),
advance_loc1: InstructionType(.{ .delta = .u8_delta }),
advance_loc2: InstructionType(.{ .delta = .u16_delta }),
advance_loc4: InstructionType(.{ .delta = .u32_delta }),
undefined: InstructionType(.{ .register = .uleb128_register }),
same_value: InstructionType(.{ .register = .uleb128_register }),
register: InstructionType(.{ .register = .uleb128_register, .target_register = .uleb128_register }),
remember_state: InstructionType(.{}),
restore_state: InstructionType(.{}),
def_cfa: InstructionType(.{ .register = .uleb128_register, .offset = .uleb128_offset }),
def_cfa_register: InstructionType(.{ .register = .uleb128_register }),
def_cfa_offset: InstructionType(.{ .offset = .uleb128_offset }),
def_cfa_expression: InstructionType(.{ .block = .block }),
expression: InstructionType(.{ .register = .uleb128_register, .block = .block }),
offset_extended_sf: InstructionType(.{ .register = .uleb128_register, .offset = .sleb128_offset }),
def_cfa_sf: InstructionType(.{ .register = .uleb128_register, .offset = .sleb128_offset }),
def_cfa_offset_sf: InstructionType(.{ .offset = .sleb128_offset }),
val_offset: InstructionType(.{ .register = .uleb128_register, .offset = .uleb128_offset }),
val_offset_sf: InstructionType(.{ .register = .uleb128_register, .offset = .sleb128_offset }),
val_expression: InstructionType(.{ .register = .uleb128_register, .block = .block }),
fn readOperands(
self: *Instruction,
stream: *std.io.FixedBufferStream([]const u8),
opcode_value: ?u6,
addr_size_bytes: u8,
endian: std.builtin.Endian,
) !void {
switch (self.*) {
inline else => |*inst| inst.* = try @TypeOf(inst.*).read(stream, opcode_value, addr_size_bytes, endian),
}
}
advance_loc: struct {
delta: u8,
},
offset: struct {
register: u8,
offset: u64,
},
offset_extended: struct {
register: u8,
offset: u64,
},
restore: struct {
register: u8,
},
restore_extended: struct {
register: u8,
},
nop: void,
set_loc: struct {
address: u64,
},
advance_loc1: struct {
delta: u8,
},
advance_loc2: struct {
delta: u16,
},
advance_loc4: struct {
delta: u32,
},
undefined: struct {
register: u8,
},
same_value: struct {
register: u8,
},
register: struct {
register: u8,
target_register: u8,
},
remember_state: void,
restore_state: void,
def_cfa: struct {
register: u8,
offset: u64,
},
def_cfa_register: struct {
register: u8,
},
def_cfa_offset: struct {
offset: u64,
},
def_cfa_expression: struct {
block: []const u8,
},
expression: struct {
register: u8,
block: []const u8,
},
offset_extended_sf: struct {
register: u8,
offset: i64,
},
def_cfa_sf: struct {
register: u8,
offset: i64,
},
def_cfa_offset_sf: struct {
offset: i64,
},
val_offset: struct {
register: u8,
offset: u64,
},
val_offset_sf: struct {
register: u8,
offset: i64,
},
val_expression: struct {
register: u8,
block: []const u8,
},
pub fn read(
stream: *std.io.FixedBufferStream([]const u8),
addr_size_bytes: u8,
endian: std.builtin.Endian,
) !Instruction {
switch (try stream.reader().readByte()) {
const reader = stream.reader();
switch (try reader.readByte()) {
Opcode.lo_inline...Opcode.hi_inline => |opcode| {
const e: Opcode = @enumFromInt(opcode & 0b11000000);
switch (e) {
inline .advance_loc,
.offset,
.restore,
=> |tag| {
var result = @unionInit(Instruction, @tagName(tag), undefined);
try result.readOperands(stream, @as(u6, @intCast(opcode & 0b111111)), addr_size_bytes, endian);
return result;
const value: u6 = @intCast(opcode & 0b111111);
return switch (e) {
.advance_loc => .{
.advance_loc = .{ .delta = value },
},
.offset => .{
.offset = .{
.register = value,
.offset = try leb.readULEB128(u64, reader),
},
},
.restore => .{
.restore = .{ .register = value },
},
else => unreachable,
}
};
},
Opcode.lo_reserved...Opcode.hi_reserved => |opcode| {
const e: Opcode = @enumFromInt(opcode);
switch (e) {
return switch (e) {
.advance_loc,
.offset,
.restore,
=> unreachable,
inline else => |tag| {
var result = @unionInit(Instruction, @tagName(tag), undefined);
try result.readOperands(stream, null, addr_size_bytes, endian);
return result;
.nop => .{ .nop = {} },
.set_loc => .{
.set_loc = .{
.address = switch (addr_size_bytes) {
2 => try reader.readInt(u16, endian),
4 => try reader.readInt(u32, endian),
8 => try reader.readInt(u64, endian),
else => return error.InvalidAddrSize,
},
},
},
}
.advance_loc1 => .{
.advance_loc1 = .{ .delta = try reader.readByte() },
},
.advance_loc2 => .{
.advance_loc2 = .{ .delta = try reader.readInt(u16, endian) },
},
.advance_loc4 => .{
.advance_loc4 = .{ .delta = try reader.readInt(u32, endian) },
},
.offset_extended => .{
.offset_extended = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readULEB128(u64, reader),
},
},
.restore_extended => .{
.restore_extended = .{
.register = try leb.readULEB128(u8, reader),
},
},
.undefined => .{
.undefined = .{
.register = try leb.readULEB128(u8, reader),
},
},
.same_value => .{
.same_value = .{
.register = try leb.readULEB128(u8, reader),
},
},
.register => .{
.register = .{
.register = try leb.readULEB128(u8, reader),
.target_register = try leb.readULEB128(u8, reader),
},
},
.remember_state => .{ .remember_state = {} },
.restore_state => .{ .restore_state = {} },
.def_cfa => .{
.def_cfa = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readULEB128(u64, reader),
},
},
.def_cfa_register => .{
.def_cfa_register = .{
.register = try leb.readULEB128(u8, reader),
},
},
.def_cfa_offset => .{
.def_cfa_offset = .{
.offset = try leb.readULEB128(u64, reader),
},
},
.def_cfa_expression => .{
.def_cfa_expression = .{
.block = try readBlock(stream),
},
},
.expression => .{
.expression = .{
.register = try leb.readULEB128(u8, reader),
.block = try readBlock(stream),
},
},
.offset_extended_sf => .{
.offset_extended_sf = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readILEB128(i64, reader),
},
},
.def_cfa_sf => .{
.def_cfa_sf = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readILEB128(i64, reader),
},
},
.def_cfa_offset_sf => .{
.def_cfa_offset_sf = .{
.offset = try leb.readILEB128(i64, reader),
},
},
.val_offset => .{
.val_offset = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readULEB128(u64, reader),
},
},
.val_offset_sf => .{
.val_offset_sf = .{
.register = try leb.readULEB128(u8, reader),
.offset = try leb.readILEB128(i64, reader),
},
},
.val_expression => .{
.val_expression = .{
.register = try leb.readULEB128(u8, reader),
.block = try readBlock(stream),
},
},
};
},
Opcode.lo_user...Opcode.hi_user => return error.UnimplementedUserOpcode,
else => return error.InvalidOpcode,
@@ -492,16 +549,16 @@ pub const VirtualMachine = struct {
const prev_row = self.current_row;
switch (instruction) {
.set_loc => |i| {
if (i.operands.address <= self.current_row.offset) return error.InvalidOperation;
if (i.address <= self.current_row.offset) return error.InvalidOperation;
// TODO: Check cie.segment_selector_size != 0 for DWARFV4
self.current_row.offset = i.operands.address;
self.current_row.offset = i.address;
},
inline .advance_loc,
.advance_loc1,
.advance_loc2,
.advance_loc4,
=> |i| {
self.current_row.offset += i.operands.delta * cie.code_alignment_factor;
self.current_row.offset += i.delta * cie.code_alignment_factor;
self.current_row.copy_on_write = true;
},
inline .offset,
@@ -509,35 +566,35 @@ pub const VirtualMachine = struct {
.offset_extended_sf,
=> |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
column.rule = .{ .offset = @as(i64, @intCast(i.operands.offset)) * cie.data_alignment_factor };
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{ .offset = @as(i64, @intCast(i.offset)) * cie.data_alignment_factor };
},
inline .restore,
.restore_extended,
=> |i| {
try self.resolveCopyOnWrite(allocator);
if (self.cie_row) |cie_row| {
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = for (self.rowColumns(cie_row)) |cie_column| {
if (cie_column.register == i.operands.register) break cie_column.rule;
if (cie_column.register == i.register) break cie_column.rule;
} else .{ .default = {} };
} else return error.InvalidOperation;
},
.nop => {},
.undefined => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{ .undefined = {} };
},
.same_value => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{ .same_value = {} };
},
.register => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
column.rule = .{ .register = i.operands.target_register };
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{ .register = i.target_register };
},
.remember_state => {
try self.stack.append(allocator, self.current_row.columns);
@@ -555,69 +612,69 @@ pub const VirtualMachine = struct {
.def_cfa => |i| {
try self.resolveCopyOnWrite(allocator);
self.current_row.cfa = .{
.register = i.operands.register,
.rule = .{ .val_offset = @intCast(i.operands.offset) },
.register = i.register,
.rule = .{ .val_offset = @intCast(i.offset) },
};
},
.def_cfa_sf => |i| {
try self.resolveCopyOnWrite(allocator);
self.current_row.cfa = .{
.register = i.operands.register,
.rule = .{ .val_offset = i.operands.offset * cie.data_alignment_factor },
.register = i.register,
.rule = .{ .val_offset = i.offset * cie.data_alignment_factor },
};
},
.def_cfa_register => |i| {
try self.resolveCopyOnWrite(allocator);
if (self.current_row.cfa.register == null or self.current_row.cfa.rule != .val_offset) return error.InvalidOperation;
self.current_row.cfa.register = i.operands.register;
self.current_row.cfa.register = i.register;
},
.def_cfa_offset => |i| {
try self.resolveCopyOnWrite(allocator);
if (self.current_row.cfa.register == null or self.current_row.cfa.rule != .val_offset) return error.InvalidOperation;
self.current_row.cfa.rule = .{
.val_offset = @intCast(i.operands.offset),
.val_offset = @intCast(i.offset),
};
},
.def_cfa_offset_sf => |i| {
try self.resolveCopyOnWrite(allocator);
if (self.current_row.cfa.register == null or self.current_row.cfa.rule != .val_offset) return error.InvalidOperation;
self.current_row.cfa.rule = .{
.val_offset = i.operands.offset * cie.data_alignment_factor,
.val_offset = i.offset * cie.data_alignment_factor,
};
},
.def_cfa_expression => |i| {
try self.resolveCopyOnWrite(allocator);
self.current_row.cfa.register = undefined;
self.current_row.cfa.rule = .{
.expression = i.operands.block,
.expression = i.block,
};
},
.expression => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{
.expression = i.operands.block,
.expression = i.block,
};
},
.val_offset => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{
.val_offset = @as(i64, @intCast(i.operands.offset)) * cie.data_alignment_factor,
.val_offset = @as(i64, @intCast(i.offset)) * cie.data_alignment_factor,
};
},
.val_offset_sf => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{
.val_offset = i.operands.offset * cie.data_alignment_factor,
.val_offset = i.offset * cie.data_alignment_factor,
};
},
.val_expression => |i| {
try self.resolveCopyOnWrite(allocator);
const column = try self.getOrAddColumn(allocator, i.operands.register);
const column = try self.getOrAddColumn(allocator, i.register);
column.rule = .{
.val_expression = i.operands.block,
.val_expression = i.block,
};
},
}